Gastral exocrine products of a myrmicine ant strongly overlap pygidial gland products of Dolichoderinae

Abstract

In most subfamilies of ants (Formicidae), a pygidial gland occurs in the worker's dorsal gaster, and where tested, products of this gland function in alarm/defense and/ or recruitment communication. These products are well characterized for members of the subfamily Dolichoderinae but remain unidentifi ed for Myrmicinae. Both major and minor workers of one myrmicine, Pheidole biconstricta Mayr, are known to have greatly hypertrophied pygidial glands with alarm/repellent products. GC/MS analysis of methanol extracts of worker gasters revealed actinidine and six diastereomers of iridodials as major components, as well as lesser amounts of two lactones, iridomyrmecin and dihydronepetalactone. The iridoids also occur in the pygidial glands of some dolichoderines. Results are related to functional and phylogenetic considerations.

Chemical signals associated with life inhibit necrophoresis in Argentine ants

“…We suggest that analogous chemical vital signs may occur in other ant species, given that various related iridoids are found in the pygidial gland secretions of many dolichoderine and myrmicine ants (18).…”

“…In distinct contrast to previous hypotheses, our results demonstrate that the decrease in chemical compounds associated with living ants, rather than an increase in compounds associated with decomposition of dead ants, is the crucial cue that elicits necrophoric behavior. Dolichodial and iridomyrmecin are produced and stored in the pygidial gland of L. humile (15,16), and this gland occurs in all ant subfamilies except the Formicinae, where it may have been lost secondarily (17,18). Volatile chemicals produced by the pygidial glands of dolichoderine and myrmicine ants are commonly thought to have alarm or defensive functions (19)(20)(21), and the less volatile constituents such as iridodials, dolichodials, and related compounds were assumed to retard the evaporation of the more volatile repellent constituents (18,20) or to act as viscous defensive agents (20)(21)(22).…”

“…Dolichodial and iridomyrmecin are produced and stored in the pygidial gland of L. humile (15,16), and this gland occurs in all ant subfamilies except the Formicinae, where it may have been lost secondarily (17,18). Volatile chemicals produced by the pygidial glands of dolichoderine and myrmicine ants are commonly thought to have alarm or defensive functions (19)(20)(21), and the less volatile constituents such as iridodials, dolichodials, and related compounds were assumed to retard the evaporation of the more volatile repellent constituents (18,20) or to act as viscous defensive agents (20)(21)(22). However, to date, the possible functions of the pygidial gland chemicals of L. humile have been largely ignored, because L. humile workers do not display alarm reactions to crushed workers (19,23).…”

Do Defensive Compounds Affect the Success of Invasion of the Argentine Ant?

“…dolichodial and iridomyrmecin), during aggressive interspeci c interactions by applying them directly on their competitor's surface. The use of iridoids directly applied on competing ants is also common on other ant species, both Dolichoderinae ants, such as Tapinoma melanocephalum and T. erraticum, and non-Dolichoderinae ants such as Pheidole biconstricta (Kugler 1979;Tomalski et al 1987;Davidson et al 2005).…”

Ant–hemipteran association decreases parasitism of Phenacoccus solenopsis by endoparasitoid Aenasius bambawalei

“…Relatively few studies have focused on the functional chemicals from insect secretions and excretions. Previous studies have determined and discussed the effects of pygidial gland extracts of ants on the behavioural response of intraspecific individuals and other ant species (Simon & Hefetz, 1991;Davidson et al, 2005;Zhou et al, 2014b). Pygidial gland secretions excreted by T. melanocephalum are effective alarm-defence cues against other aggressive ants (Tomalski et al, 1987).…”